[Previous entry: "Israel's existence uncertain"] [Next entry: "Primates reveal different levels of boundary-based reasoning"]
09/10/2007: "Under traditional societies, the poor bred less"
We found the highest opportunity for total selection and the strongest selection on earlier age at first reproduction in women of the poorest wealth class, whereas selection favoured older age at reproductive cessation in mothers of the wealthier classes. We also found clear differences in female life-history traits across wealth classes: the poorest women had the lowest age-specific survival throughout their lives, they started reproduction later, delivered fewer offspring during their lifetime, ceased reproduction younger, had poorer offspring survival to adulthood and, hence, had lower fitness compared to the wealthier women. Our results show that the amount of wealth affected the selection pressure on female life-history in a pre-industrial human population.
Lummaa's data is from the 18th and 19th century in Finland, but in many ways it is generalizable. In post-demographic transition societies we are faced with the fact that the lower social classes tend to be more fecund, but for most of human history this was not an operative dynamic. I believe
some of the resistance to Greg Clark's contention that the wealthy gentry were the predominant ancestors of the modern British population is simply due to its relative counter-intuitiveness to the modern middle class, who simply can't believe that anyone responsible would breed to their maximal
reproductive capacity.
http://www.gnxp.com/blog/2007/09/in-days-of-yore-wealthy-were-healthy.php
[ We used to have a functional natural selection. The ages of material wealth and exploding cities are an execption in that the poor and dysfunctional are the fecund kings. ]
[A] speed dating sample from last year with a sample size of 400 found the
same things among college students:
"Women put greater weight on the intelligence [As measured by SAT score] and the race of partner, while men respond more to physical attractiveness."
http://www.gnxp.com/blog/2007/09/what-women-want.php